Modelling of Intensively Blasted Electric Arc

Abstract

The paper deals with a simplified model of an intensively blasted electric arc burning in the anode chan-nel of an arc heater. The model is based on the energy conservation law, continuity equation and Ohm’s law. For computation, transport and thermodynamic properties of working medium and real experimental results describing the external manifestation of the arc are necessary. Many experimental data have been collected during numerous experiments made out with a modular arc heater operated under various ex-perimental conditions, each experiment being characterized by the arc current, voltage, the sort and flow rate of working gas, and the flow rates and temperatures of cooling water in individual segments of the device. In the presented model a rectangular temperature profile of the arc is used. A dependency of the arc column radius rA on the distance from the cathode is prescribed and parameters of the function rA(z) are estimated using the total power balance at the output cross-section of the anode channel. Special at-tention is paid to the region near the beginning. The dependencies of the arc temperature and electric field intensity on the distance from the cathode are calculated and iterations are stopped if the sums of computed increments agree with the measured values. Computed dependencies are given in diagrams and discussed.